Overview
The purpose of this study is to evaluate the efficacy and safety of inavolisib in combination with fulvestrant compared with inavolisib in combination with fulvestrant in participants with PIK3CA-mutated, HR-positive, HER2-negative locally advanced or metastatic breast cancer (LA/mBC) in the post-cyclin-dependent kinase inhibitor (CDKi) setting.
Eligibility
Inclusion Criteria:
- Documented ER +/ HER2- tumor according to American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines
- Disease progression after or during treatment with a combination of CDK4/6i and endocrine therapy: \<= 1 prior lines of systemic therapy in the locally advanced (recurrent or progressed) or metastatic setting
- Measurable or evaluable disease per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1)
- Participants for whom endocrine-based therapy is recommended and treatment with cytotoxic chemotherapy is not indicated at time of entry into the study, as per national or local treatment guidelines
- Confirmation of biomarker eligibility: presence of \>= 1 study-eligible PIK3CA mutation
- Life expectancy of \> 6 months
- Ability, in the investigator's judgment, and willingness to comply with all study -related procedures, including completion of patient-reported outcomes
Exclusion Criteria:
- Metaplastic breast cancer
- Prior treatment with chemotherapy in the recurrent locally advanced/metastatic setting
- Type 2 diabetes requiring ongoing systemic treatment at the time of study entry; or any history of Type 1 diabetes
- Prior treatment with PI3K/Akt/mTOR inhibitors in the recurrent locally advanced/metastatic setting
- Requirement for daily supplemental oxygen
- Symptomatic active lung disease, including pneumonitis